Camera Donny M, Hawley John A, Coffey Vernon G
Exercise and Nutrition Research Group, School of Exercise Science, Australian Catholic University, 8-18 Brunswick St, Fitzroy, VIC, 3165, Australia,
Eur J Appl Physiol. 2015 Jun;115(6):1185-94. doi: 10.1007/s00421-015-3116-x. Epub 2015 Feb 4.
We determined the effect of reduced muscle glycogen availability on cellular pathways regulating mitochondrial biogenesis and substrate utilization after a bout of resistance exercise.
Eight young, recreationally trained men undertook a glycogen depletion protocol of one-leg cycling to fatigue (LOW), while the contralateral (control) leg rested (CONT). Following an overnight fast, subjects completed 8 sets of 5 unilateral leg press repetitions (REX) at 80 % 1 Repetition Maximum (1RM) on each leg. Subjects consumed 500 mL protein/CHO beverage (20 g whey + 40 g maltodextrin) upon completion of REX and 2 h later. Muscle biopsies were obtained at rest and 1 and 4 h after REX in both legs.
Resting muscle glycogen was higher in the CONT than LOW leg (384 ± 114 vs 184 ± 36 mmol kg(-1) dry wt; P < 0.05), and 1 h and 4 h post-exercise (P < 0.05). Phosphorylation of p53(Ser15) increased 1 h post-exercise in LOW (115 %, P < 0.05) and was higher than CONT at this time point (87 %, P < 0.05). p38MAPK(Thr180/Tyr182) phosphorylation increased 1 h post-exercise in both CONT and LOW (800-900 %; P < 0.05) but remained above rest at 4 h only in CONT (585 %, P < 0.05; different between legs P < 0.05). Peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α) mRNA was elevated 4 h post-exercise in LOW (200 %, P < 0.05; different between legs P < 0.05). There were no changes in Fibronectin type III domain-containing protein 5 (FNDC5) mRNA for CONT or LOW legs post-exercise.
Undertaking resistance exercise with low glycogen availability may enhance mitochondrial-related adaptations through p53 and PGC-1α-mediated signalling.
我们确定了一次抗阻运动后，肌肉糖原可用性降低对调节线粒体生物合成和底物利用的细胞途径的影响。
八名年轻的、有休闲运动训练经历的男性进行了单腿骑行至疲劳的糖原耗竭方案（LOW），而对侧（对照）腿休息（CONT）。经过一夜禁食后，受试者在每条腿上以80%的1次重复最大值（1RM）完成8组每组5次的单侧腿举重复动作（REX）。受试者在完成REX后及2小时后饮用500毫升蛋白质/碳水化合物饮料（20克乳清蛋白+40克麦芽糊精）。在休息时以及REX后1小时和4小时从双腿获取肌肉活检样本。
CONT腿的静息肌肉糖原高于LOW腿（384±114 vs 184±36毫摩尔/千克干重；P<0.05），且运动后1小时和4小时也是如此（P<0.05）。LOW腿运动后1小时p53（Ser15）的磷酸化增加（115%，P<0.05），且在该时间点高于CONT腿（87%，P<0.05）。CONT腿和LOW腿运动后1小时p38丝裂原活化蛋白激酶（Thr180/Tyr182）的磷酸化均增加（800 - 900%；P<0.05），但仅CONT腿在4小时时仍高于静息水平（585%，P<0.05；两腿之间差异P<0.05）。LOW腿运动后4小时过氧化物酶体增殖物激活受体γ共激活因子-1α（PGC-1α）mRNA升高（200%，P<0.05；两腿之间差异P<0.05）。运动后CONT腿和LOW腿含III型纤连蛋白结构域蛋白5（FNDC5）的mRNA均无变化。
在糖原可用性较低的情况下进行抗阻运动可能通过p53和PGC-1α介导的信号增强线粒体相关适应性。
